Post by swampgas on Jan 11, 2004 13:17:32 GMT -5
Hundreds of thousands of tonnes of metallic 'scatterers' would be ejected into the upper atmosphere under the plans.
www.guardian.co.uk/climatechange/story/0,12374,1120510,00.html
Giant space shield plan to save planet
Mark Townsend
Sunday January 11, 2004
The Observer
Humanity could not exist without it - yet in an extraordinary plan that underlines the catastrophic implications of climate change, scientists now want to curb the Sun's life-giving influence to save mankind from its biggest threat: global warming.
Key talks involving the Government's most senior climate experts have produced proposals to site a massive shield on the edge of space that would deflect the Sun's rays and stabilise the climate.
Hundreds of thousands of tonnes of metallic 'scatterers' would be ejected into the upper atmosphere under the plans. In addition, billions of tiny barrage balloons could serve as a secondary barrier to block rays from the Earth's nearest star.
On land, giant reservoirs holding saline water could be built to offset the rise in sea levels caused by the melting of the polar ice-caps. The oceans, too, would be modified to cope with the planet's increasingly warmer weather. Massive floating cloud-making machines would be dotted across their surface while, below, large plantations of algae would be grown to absorb greenhouse gases from the atmosphere.
The theories were discussed by Britain's most eminent climatologists at a meeting in Cambridge last week to analyse the latest theories to tackle the problem of the planet heating up. They included the Government's chief scientist, Sir David King, who warned last week that climate change was the most severe problem facing civilisation.
Professor John Schellnhuber, former chief environmental adviser to the German government and head of the UK's leading group of climate scientists at the Tyndall Centre, said: 'These are exotic ideas and we probably will have to come up with the right mixture. But the problem has not gone away, so we think this analysis is just in time.
'The present climate policy does not seem to be working. We are not saying we have the magic bullet, but this is a desperate situation and people should start thinking about the unconventional. Preventative plans on a larger scale are needed.'
Environmentalists maintain that the solutions are so radical they serve only to underscore how unprepared governments are to deal with the threat. Last week researchers predicted that a quarter of land animals and plants will die out because of global warming over the next 50 years.
Scientists, however, argue that until the United States and Russia ratify international agreements to limit the emission of greenhouse gases they will have little choice but to explore new methods to save the planet.
Extreme technological fixes include deploying tens of billions of wafer-thin metal plates less than a centimetre wide into the Earth's low orbit via space rockets. These would be specially built to allow space-bound rays to pass while at the same time absorbing a significant amount of solar energy before bouncing it back into space. They would be designed to stay in place for a century.
Similar solutions include the release of massive nets of ultra-fine metal mesh into the upper atmosphere by aircraft to prevent the Sun's rays from reaching Earth. Alternatively, millions of metallic-coated super-pressure balloons - similar in design to a children's party version, although a fraction of the size - would be filled with helium and released until they reach the stratosphere 35,000ft above the Earth. Trapped in parcels of air, they would stay up for about five years before falling to earth and being replaced.
All the methods are designed to block about 1 per cent of the Sun's rays, enough to protect at least one million square kilometres of the Earth and significantly cool the planet.
Inspiration came from studying the effects of volcanic eruptions in Indonesia in 1814. During these explosions, enough material was spewed into the upper atmosphere to cause temperatures to fall by up to 30 per cent for almost three years, roughly the amount some predict that they will rise to by the end of this century.
Academics from California's Lawrence Livermore National Laboratory, who told government scientists about the billion-pound scheme, claim it will increase crop yields, because plants would be less damaged by the Sun's harmful rays. The scheme would create more spectacular sunrises and sunsets, deeper blue skies and would reduce the cancer risk for sunbathers and children.
Pumping nutrients into the world's oceans remains another weapon under consideration. This would encourage the growth of vast underwater algae blooms to absorb carbon dioxide from the atmosphere. Scientists believe 'large-scale ocean fertilisation' could act as a substitute for the world's disappearing forests, which act as a huge natural sponge for soaking up carbon dioxide from the air.
Massive floating cloud-making machines could also become a feature of the oceans. These solar-powered contraptions would spray seawater droplets of a precise size into the sky to help encourage the formation of low-level clouds.
Other ideas being looked at include the burial of carbon dioxide emissions underground. Friends of the Earth climate campaigner Roger Higman said: 'Climate change is the biggest environmental threat the world faces. It is important for scientists to explore imaginative ways to tackle its impacts, but technical fixes must not be used as an excuse for failing to reduce the growing levels of greenhouse gases.'
This week the Government will announce how it proposes to implement the most significant piece of climate change legislation since the Kyoto protocol, Europe's greenhouse gas emissions trading scheme.
